## National Population Projections

In this activity, students examine the United States Census Bureau Web site to investigate population projections from 1990-2100. Using the five provided pyramids, students analyze the data to determine

how the population is distributed over time, and explain what factors might contribute to these trends.

To introduce this activity, review the concept of population projections with the class. If you would like additional background information on "projections", visit the U.S. Census Bureau site for a detailed explanation.

Once students understand that projections are estimates of the population for future dates, display the provided population pyramid and lead a class discussion using the following questions.

(The population pyramid is entitled, "Resident Population of the United States as of July 1, 1990, Middle Series.").

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Suggestions for guiding questions to investigate the July 1, 1990 population pyramid include:

- With a partner, look at this graph and discuss what it represents. What is listed on the Y-axis? What is represented by the X-axis?
- Where is zero percent of the population listed?
- Does this mean that there is no one in that age group?
- How is the population distributed over this graph?
- What age group represents the largest portion of the population?
- In what years were these people born? (Remember that this graph represents 1990)
- What age group represents the smallest portion of the population?
- In what year were they born?

For the next part of the lesson, place students into teams of two and distribute a National Population Projections Activity Sheet to each pair.

National Population Projections Activity Sheet

Students should visit the website indicated at the top of the activity sheet.Once at the Web site, students will investigate population projection data for the United States over a 110-year period. They will analyze five specific population pyramids. The students should also examine how the population data is distributed over time and explain what factors might contribute to these trends.

Working together, partners share the responsibilities of "Mouse Driver" and "Reader/Recorder." The "Reader/Recorder" will read the directions from the activity sheet and record observations while guiding the activity. The "Mouse Driver" controls the action of the mouse and movement on the computer screen. Partners should switch roles until both have moved the mouse and investigated the five population pyramids.

The pyramids are listed in chronological order from 1990, 2000, 2025, 2050, and 2100. Once the teams have completed the activity sheets, lead a class discussion using the questions found on the activity sheet.

As a concluding activity, share with the class the questions each pair wrote about how the distribution of the population changed over the 110-year period. Be sure to discuss the following:

- Why is this information important to the United States Government?
- What did you learn about population during this activity?
- What other questions do you have that you could follow up on in future studies of this data?

**Questions for Students**

Refer to the Instructional Plan.

### State Population Projections

information.

### Learning Objectives

Students will:

- Analyze population projections for the United States.
- Describe the shape and important features of that data set, with an emphasis on how the data are distributed over time.

### NCTM Standards and Expectations

- Represent data using tables and graphs such as line plots, bar graphs, and line graphs.

- Recognize the differences in representing categorical and numerical data.

- Describe the shape and important features of a set of data and compare related data sets, with an emphasis on how the data are distributed.

### Common Core State Standards – Practice

- CCSS.Math.Practice.MP3

Construct viable arguments and critique the reasoning of others.